In equipment having at least two load devices (e.g., plural modules, units, or subsystems) that require electrical power, a shared power source that supplies power to these devices or subsystems is typically designed to meet the worst case loads of all supported equipment with some margin. However, designing the shared power source for the combined peak power requirements of all of the supported equipment results in increases in size and cost of the power supply and reduces power supply efficiency under average loads which may more commonly occur during operation. Such an approach does not take advantage of load leveling when average loads are much lower than peak loads.
Recent advances in technology, such as aerogel-based supercapacitors, have allowed newer systems to be designed for average power instead of worst-case peak power. However, present shared power schemes still have a number of limitations. For example, the power requirements of any individual load device supported by the shared power subsystem may vary over time by an order of magnitude or more depending on the operating state of the equipment. Shared power subsystems are generally not designed to take advantage of such varying load conditions imposed by the supported equipment or to manage or coordinate the collective time-varying power requirements of the supported equipment.
A power supply module or subsystem originally designed to support certain equipment subsequently may be required to additionally support new modules or equipment that augments or enhances the original equipment. If it is desirable not to modify or redesign the power subsystem, supporting this additional equipment may put a strain on the available power resources, since there will be some upper limit on the current the power subsystem can supply.
For example, legacy communication equipment lacking some of the capabilities of expected of future software defined radios or radios conforming to the U.S. government's Software Communication Architecture, can be greatly enhanced by attaching a separate module which is compatible with the legacy equipment and provides many of the more advanced capabilities and flexibility of a software defined radio. Preferably, such an expansion module would connect to an existing or legacy communication device in such a manner that the module provides additional capabilities to the existing device without the need for wholesale removal and exchange of the existing device with a new device. To make retrofitting of legacy equipment cost effective, it is desirable minimize modifications to the original equipment, including the power subsystem. In such situations, consideration must be made as to how to share among multiple subsystems a limited amount of power originally expected to support fewer components, while still meeting the power requirements of each subsystem.
More generally, it would be desirable to provide a scheme which manages and coordinates usage of a shared power source among a plurality of load devices, some of which may have time-varying power requirements and/or a controllable duty cycle, in a manner that minimizes the average power requirements of the shared power source.